Preheat oven to 350 degrees F (175 degrees C). Grease and flour a muffin pan, or use paper liners. In a saucepan over medium-high heat, combine dates, raisins, prunes, and water. Boil for 5 minutes, then stir in butter and salt; set aside to cool.
When fruit mixture is cool, transfer to a large bowl. Beat in eggs and vanilla. Stir together flour, baking soda and baking powder, then blend into fruit mixture. fold in nuts. Spoon into muffin cups 2/3 to 3/4 full.
Bake in the preheated oven for 15 to 20 minutes, or until a toothpick inserted into the center comes out clean. Allow to cool.
